环状压电陶瓷复合变压器径向振动的研究

new structure of annular piezoelectric ceramic composite transformer in radial vibration is proposed and its characteristics are researched. The new piezoelectric transformer consists of two concentric piezoelectric ceramic rings and a metal ring in the radial direction. By deducing the electro-mechanical equivalent circuit of the piezoelectric composite transformer, the equations of resonance/ anti-resonance frequency, voltage gain and efficiency are obtained. The dependences of the electromechanical characteristics (resonance frequency, effective electro-mechanical coupling coefficient, voltage gain and efficiency) on geometrical dimension of the metal ring, the mechanical loss and load impedance are analyzed. To verify the analytical theory, the frequency and voltage gain of piezoelectric transformers are measured. It is shown that the experimental results are in good agreement with the analytical results.